If useful life is: The applicable percentage is:
Less than 6 years ........................................ 33 1/3
6 years or more but less than 8 years .................... 66 2/3
8 years or more .......................................... 100
The useful life of any property for purposes of this section shall be determined as of the date such property is first placed in service or use in this state by the taxpayer, determined in accordance with federal income tax law.
In no event shall "qualified research expenses" include any expense that must be capitalized and depreciated for federal income tax purposes, or any expenditure paid or incurred for the purpose of ascertaining the existence, location, extent or quality of any deposit of coal, limestone or other natural resource, including oil and natural gas.
If substantially all of the services performed by an individual for the taxpayer during the taxable year consist of services meeting the requirements of subparagraph (A) or (B), the term "qualified services" means all services performed by such individual for the taxable year.
W. Va. Code § 11-13D-5